Nickel salts of iminoheterocyclicamides

ABSTRACT

HIGHLY COLORED NICKEL SALTS OF CHELATES OF IMINOHETEROCYCLIC CARBOXAMIDS OR CARBOTHIAMIDES SUITABLE AS PIGMENTS ARE DESCRIBED. THE NICKEL SALTS ARE PREPARED BY REACTING A NICKEL HALIDE OR A NICKEL SALT OF A WEAK ACID WITH THE DESIRED IMINOHETEROCYCLIC CARBOXAMIDE OR CARBOTHIAMIDE, AS FOR EXAMPLE, WITH 2-IMINOCOUMARIN-3-CARBOXAMIDE, WHICH IN TURN CAN BE PREFORMED OR FORMED IN SITU BY CONDENSING THE APPROPRIATE ALDEHYDE WITH A CYANOACETAMIDE OR CYANOTHIOACETAMIDE. PIGMENTARY MIXED CHELATES ARE ALSO FORMED IN THE SAME MANNER BY REACTING THE NICKEL SALT WITH A MIXTURE OF THE DESIRED IMINOHETEROCYCLIC CARBOXAMIDE OR CARBOTHIAMIDE AND AT LEAST ONE OTHER CHELATING AGENT SUCH AS, FOR EXAMPLE, DIMETHYLGLYOXIME, 1NITROSO-2-NAPHTHOL, ETC.

United States Patent 3,576,012 NICKEL SALTS F IMINOI-IETEROCYCLICAMIDESAlbert S. Matlack, Hockessin, DeL, assignor to Hercules Incorporated NoDrawing. Filed Nov. 2, 1967, Ser. No. 680,037 Int. Cl. C07d 7/20 US. Cl.260-345.2 3 Claims ABSTRACT OF THE DISCLOSURE Highly colored nickelsalts or chelates of iminoheterocyclic carboxamides or carbothiamidessuitable as pigments are described. The nickel salts are prepared byreacting a nickel halide or a nickel salt of a weak acid with thedesired iminoheterocyclic carboxamide or carbothiamide, as for example,with 2-iminocoumarin-3carboxamide, which in turn can be preformed orformed in situ by condensing the appropriate aldehyde with acyanoacetamide or cyanothioacetamide. Pigmentary mixed chelates are alsoformed in the same manner by reacting the nickel salt with a mixture ofthe desired irninoheterocyclic car boxamide or carbothiamide and atleast one other chelating agent such as, for example, dimethylglyoxime,1- nitroso-Z-naphthol, etc.

This invention relates to novel nickel compounds which are nickel saltsof iminoheterocyclic carboxamides or carbothiamides and which findsignificant utility as pigments.

More specifically, the present invention is directed to water-insolublenickel salts having the formula wherein R is hydrogen, NHalkyl, NHacyl,NHaryl, NHaralkyl, N=CHaryl or a heterocyclic substituted alkyl group; Xis oxygen or sulfur; X is oxygen, sulfur, NR or CHR where R is hydrogenor an inert organic radical; y is oxygen, sulfur, NR or together with Xforms a -7 membered ring; Z is nitrogen, N- O or CR where R is hydrogen,hydroxyl or a hydrocarbon group; Z is nitrogen or CR where R ishydrogen, an inert organic or inorganic radical, or together with Rforms a 5-7 membered ring; Z is nitrogen or CR where R is hydrogen,hydroxyl, an inert organic radical, or together with R forms a 5-7membered ring; Z is nitrogen or CR where R is hydrogen, an inert organicradical, or together with X forms a 5-7 rembered ring; A is anion; m is0 or 1; n is 1 or 2; and v is the valence of anion A, with the furtherprovision that at least one of Z, Z and Z contains carbon.

In the above formulae, R as stated in hydrogen, NHalkyl, NHacyl, NHaryl,NHaralkyl, N: CHaryl or a heterocyclic substituted alkyl group. When Ris NHalkyl, the alkyl group preferably contains 1 to carbon atoms andis, for example, methyl, ethyl, n-propyl isopropyl, butyl, isobutyl,tert-butyl, pentyl,

hexyl,

octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, 2- ethylhexyl,2-cyclohexylethyl and the like. When R is NHacyl, the acyl grouppreferably contains 2 to 20 carbon atoms and is, for example, acetyl,propionyl, butanoyl, pentanoyl, decanoyl, octadecanoyl, benzoyl,phenylacetyl and the like. The aryl groups in NHaryl, NHaralkyl andN=CHaryl can comprise phenyl, lnaphthyl, 2-naphthyl, xylyl,4-methoxyphenyl and 4- chlorophenyl groups, the aralkyl groupspreferably being phenalkyl groups such as benzyl, phenethyl and thelike. The heterocyclic substituted alkyl groups are typically picolyl,methylpicolyl, dimethylpicolyl and the like.

The inert organic radicals which R R R and R can comprise are numerousand varied and are preferably hydrocarbon or substituted hydrocarbongroups such as alkyl groups containing 1 to 20 carbon atoms, aryl orcycloalkyl groups containing 6 to 18 carbon atoms, aralkyl or alkarylgroups containing 7 to 19 carbon atoms or any of the above groups alsocontaining oxygen, sulfur and/ or nitrogen substituents. Particularlypreferred groups which R can comprise include alkyl, alkoxy, carbamoyl,sulfonamide, alkoxycarbonyl and the like. The hydrocarbon groups which Rcan comprise are preferably alkyl groups containing 1 to 20 carbonatoms, aryl groups containing 6 to 18 carbon atoms, and alkaryl oraralkyl groups containing 7 to 19 carbon atoms. The preferred inertinorganic radicals which R can also comprise include cyano, nitro,tric'hloromethyl, trifluoromethyl, sulfamoyl, carbamoyl and the like. A,as stated, is an anion of valence v. Preferred anions include halide,alkanoate, thiocyanate, cyanide, sulfate, nitrate, phosphate andhydroxide, and most preferably chloride, bromide, thiocyanate, cyanide,sulfate, nitrate, phosphate, hydroxide, acetate, propionate,2-ethylhexanoate, octanoate and the like.

The nickel compounds of the present invention are highly colored,insoluble salts which range in color from orange to red to maroon. Thestructure of the nickel compounds, as given above, has not beenestablished unequivocally. However, from the nature of several analogs,it appears that an essential feature of the nickel salt or chelate (assuch salts are often referred to) is a sixmembered ring containing 2nitrogen atoms and one nickel atom. Hence, it is postulated that thenickel-containing ring has the structure X II NHR

)111 where X, R and m are as defined above. It is understood, of course,that the exact hydrogen which is replaced by nickel is not known withcertainty. It is also postulated that the ring adjacent to thenickel-containing rin'g must contain a minimum of one hetero atom whichcan be nitrogen, oxygen or sulfur, a minimum of 3 carbon atoms, and aconjugated system of alternating single and double bonds.

Exemplary of compounds represented by Formula I above are the nickelsalts of the 2-imino-2H-1-pyran-3- carboxamides,Z-imino-ZH-1thiapyran-3carboxamides, 1,2-dihydro-2-irninopyridine-3-carboxamides, 1,6-dihydro-6-iminopyridazine-S-carboxamides,1,6-dihydro-6-iminopyrirnidine-S-carboxamides, 1,2dihydro-Z-iminopyrazine- 3 carboxamides, 6 imino 6H 1,2oxazine-S-carboxamides, 6-imino-6H,1,3-oxazine-5-carboxamides, 2-imino-2-H-1,4-oxazine-3carboxamides, 6-imino-6H-1,2-thiazine- S-carboxamides,6-imino-6H-1,3thiazine-S-carboxamides, 2 imino2H-1,4-thiazine-3carboxamides, 1,6-dihydro-6-imino-1,2,4-triazine-5-carboxamides, 1,6-dihydro-6-imino-1,3,4-triaziue-5-carboxamides, 6-imiuo-6H-1,2,4-oxadiazineS-carboxamides, 6-imino-6H-1,3,4-oXadiazine-5-carboxamides,'6-imino-6H-l,2,4-thiadiazine-S-carboxamides, and6-imino-6H-1,3,4-thiadiazine-S-carboxamides, as well as thecorresponding carbothiamides of the above compounds. Typical compoundsrepresented by Formula II above are the nickel salts of the2,5-dihydro-2-imino-5- oxofuran-S-carboxamides,2,5-dihydro-2-imino-S-thioxofuran-3-carboxamides,2,5-dihydro-2,S-diiminofuran-3-carboxamides,2,5-dihydro-2-imino-S-Substituted iminofuran- 3-carboxamides,5-alkylidene-2,S-dihydro-2-iminofuran-3- carboxamides,2,5-dihydro-2-imino-5-oxothiophene-3-carboxamides, 2,5dihydro-Z-imino-5-thioxothiophene-3-carboxamides,2,5-dihydro-2,5-diiminothiophene-3-carboxamides,2,5-dihydro-2-imino-S-substituted iminothiophene- 3 carboxarnides, 5alkylidene-Z,S-dihydro-Z-iminothiophene-3-carboxamides, 2-imino-5-oxo-Apyrroline-3-carboxamides, 2-imino-5-thioxo-A pyrroline-3-carboxarnides,'

2,5 dijmino-Mpyrroline-B-carboxamides, Z-imino-S-substituted imino-Apyrroline-3-carboxamides, S-alkylidene- 2-imino-ZH-1,4-thiazine-3-carboxamides, 1,6-dihydro-6- boxamides,2,S-dihydro-Z-imino-5-thioxothiophene-3-car- 2 imino Apyrroline-3-carboxamides, S-invrino-Z-oxo-A oxazoline-4-carboxamides.S-imino-Z-thioxo-A oxazoline- 4-cal boxamides, 2,5-diimino-Aoxazoline-4-carboxarnides, S-iminio-Z-substituted imino-Aoxazoline-4-carboxamides, 2 alkylidene 5 imino-Aoxazoline-4-carboxamides, 5- imino-Z-oxo-A thiazoline-4-carboxamides,5-imino-2-thix0 A thiazoline-4-carboxamides, 2,5-diimino-Athiazoline-4-carboxamides, S-imino-Z-substitutedimino-Mthiazoinle-4carboxamides, 2-alkylidene-5-imino-A thiazoline-4-carboxamides, imino 2-oxo-A imidazoline-4-carboxamides,5-imino-Z-thioxo-A imidazoline-4-carb0xamides, 2,S-diimino-Aimidazoline-4-carboxamides, 5-imino-2-substituted imino-Aimidazolinet-carboxamides, and 2-alkylidene-S-imino-Aimidazoline-4-carboxamides, as well as the corresponding carbothiamidesof the above compounds.

The preferred compounds of the invention include such nickel salts asthose of the 2-imino-2H-1-benzopyran-3- carboxamides or -carbothiam-ides(otherwise known as and referred to hereinafter as theZ-iminocournarin-El-carboxamides or -carbothiamides), the1-a1ky1-1,2-dihydro-2- iminobenzopyridine-3-carb0xamides or-carbothiamides (otherwise referred to as the1-alkyl-1,2-dihydro-2-iminoquinoline-B-carboxamides or -carbothiamides)and the 1- aryl 1,6 dihydro 6-iminopyridazine-S-carboxarnides or-carbothiamides. Particularly preferred are the nickel salts of the2-iminocoumarin-3-carboxamides or -oarbothiamides having the formula R Xl 0 6 5 /4\3/ \NHR 7 i 1 2i iii/2 8 OAN Where R, R X and m are asindicated above, such as the nickel salts of2-oximinocoumarin-3-carboxamide, 2imino-fi-methylcoumarin-3-carboxamide,Z-iminoJ-methylcoumarin-3-carboxamide, 2-irnino-8-methylcoumarin-3-carboxamide, 2 irnino-6-tert-octylcournarin-3carboxamide,2-imino-6,8-dimethylcoumarin-3-carboxamide, S-tertbutyl 2imino-6-methylcoumarin-3-carboxamide,6-tertbutyI-Z-imino-S-methylcoumarin-3-carboxamide, 6-chloro-Z-iminocoumarin-3-carboxamide, 6-tert-butyl-8-chloro2-irninocoumarin-3-carboxarnide, 6,8-dichloro-2-iminocoumarin 3carboxarnide, 6-bromo-2-iminocoumarin-3-carboxamide,6,8-dibromo-2-iminocoumarin-3-carboxamide, 7 hydroxyZ-iminocoumarin-3-carboxamide, 2-imino-6- methoxycoumarin-3-carboxamide,2-imino-7-methoxycoumarin-3-carboxamide,Z-imino-8-methoxycoumarin-3-carboxamide,2-imino-6-methylthiocoumar-iu-3-carboxamide,Z-imino-7-trifluoromethylcoumarin-B-carboxamide, 2 im- 4ino-6-nitrocoumariu-3-carboxamide, Z-iminO-S-nitrocoumarin 3carboxamide, 2-im-ino-6-phenylazocoumarin-S- carboxamide, 7dimethylamino-Z-iminocoumarin-3-carboxamide,2-imino-5,6-benzocoumarin-3-carboxamide, 2-imino-6,7-benzocoumarin-3-carboxamide,8-bromo-2-iminc-5,6-benzocoumarin-3-carboxamide, *6-benzenesulfonyl-2-iminocoumarin-3-carboxamide, and the like, and the 3- carbothiamideanalogs of any of the above compounds.

Another particularly preferred class are the 1-aryl-1,6- dihydro 6iminopyridazine 5 carboxamides or carbothiamides such as1,6-dihydro-6-imino-1-(4-nitrophenyl pyridazine-S- carboxamide,

1- (4-chlorophenyl) -1,6-dihydro-6-iminopyridazine- 5 -carbox amide,

1-(2,4,6-trichlorophenyl)-1,6-dihydro-6-iminopyridazine-S-carboxamide,

l-(2,5-dichlorophenyl) ,6-dihydro-6-iminopyridazine- S-carboxamide,

1- 3-trifiuoromethylphenyl)-1,6-dihydro-fi-iminopyridazine-S-carboxamide,

1,6-dihydro-6-imino-1- 4-methoxyphenyl) pyridaZine-S- carboxamide,

1,6-dihydro-6-imino-1- (Z-methylphenyl) pyridazine-S- carboxarnide,

1,6-dihydro-6-in1ino-1- 3-methylphenyl) pyridazine-S- carboxamide,

1- (4-ethoxyphenyl) -l ,6-dihydro-6-iminopyridazine-5- carboxamidc,

1-(3-benzenesulfonylphenyl)-1,6-dihydr0-6-iminopyridazine-S-carboxamide,

1-(3-carbarnoylphenyl)-1,6-dihydro-G-iminopyridazine- S-carboxamide,

1 ,6-dihydro-1- (4-hydroxyphenyl) -6-iminopyridazine- S-carboxamide,

and the corresponding carbothiamides, and the l-alkyl- 1,6 dihydro 6iminopyridazine 5 carboxamides or -carbothiamides such as the 16-dihydro-6-imino-I-methylpyridazine-S-carboxarnide,l-ethyl-1,G-dihydro-6-iminopyridazine-S-carboxamide,l,6-dihydro-6-imino-l-propylpyridazine-5-carboxamide,l-butyl-1,G-dihydro-6-iminopyridazine-S-carboxamide,1-(2-ethylhexyl)-1,6-dihydro-6-irninopyridazine-5- carboxamide or thecorresponding carbothiamides. The pyridazine ring can also containsubstituents other than those listed above, as for example, keto, ester,amido, sulfon-amido or aryl groups, particularly in the 3 position.Typical of such substituents are acetyl, propionyl, benzoyl, cyano,carbamoyl, benzenesulfonyl, ethoxycarbonyl, methoxycarbonyl,phenoxycarbonyl, phenyl, 2,5-dichl0rophenyl, 4-methoxypheny1, sulfamoyland the like.

Still another most preferred class of compounds are the nickel salts ofthe 1,Z-dihydro-Z-iminoquinoline-3- carboxamides such as, for example,1,2-dihydro-2-imino-l-methyl-quinoline-S-carboxamide,l-ethyll,2-dihydr0-2-iminoquinoline-3-carb oxamide,1,2-dihydro-2-imino-1-propylquinoline-3 -carboxamide,1-(2-ethylhexyl)-1,2-dihydro-2-iminoquinoilne-3- carboxamide, l-(benzyl)-1,Z-dihydro-2-iminoquinoline-3- carboxamide,

l- 2,5 -dichlor0benzyl) 1 ,2-dihydro-2-imino quinolinecarboxamide,

l-cyclohexyl-1,Z-dihydro-2-iminoquinoline-3- carboxamide,

1,2-dihydro-2-imino-1-(4-nitrobenzyl quinoline- 3-carboxamide,

l-carboxyrnethyl-l,Z-dihydro-2-iminoquinoline-3- carboxamide,

l- (2-cyanoethyl) -1,Z-dihydro-Z-i1ninoquinoline-3- carboxamide,

1-carbamoylrnethyl-1,2-dihydro-2-iminoquinoline-3 carboxamide,1-(2-chloroethyl)-1,2-dihydro-Z-iminoquinoline-3- carboxamide,1,2-dihydro-2-imino-1-methoxycarbonylmethylquinoline- 3 -carboxamide,1,2-dihyd ro-2-imino- 1- 3-sulfop ropyl) quinoline-3 carboxamide,1,2-dihydro2-imino-1-(2,4-dinitrophenyl) quinoline- 3 -carboxamide,1,2-dihydro-2-imino-1-(4-sulfamoylphenyl) quinoline- 3-carboxamide,1,2-dihydro-2-imino- 1 4-nitrophenyl) quinoline-3- carboxamide,1,2-dihydro-2-imino- 1 -phenylquinoline-3 -carboxamide, l-2,4-diacetylphenyl) l ,2-dihydro-2-iminoquinoline- 3 -carboxamide,4-carboxy-l-methyl-1,2-dihydro-2-iminoquinoline 3-carboxamide, and

the corresponding carbothiamides. Inert substituents can also be presentin the 5, 6, 7 and 8 positions, the halo, alkyl, alkoxy and aryl groupsbeing particularly preferred.

The novel compounds of this invention can be prepared by adding asolution of a nickel salt of a weak acid or a solution of a nickelhalide and then a base such as sodium hydroxide, potassium hydroxide,ammonia, triethylamine, sodium carbonate, sodium acetate or the like toan agitated solution or dispersion of the desired iminoheterocycliccarboxamide or carbothiamide in a suitable diluent or solvent usingheat, if desired, and then isolating the nickel precipitate byconventional techniques. Preferred solvents for the nickel salt includewater, methanol, ethanol, 2-methoxyethanol, dimethylformamide and thelike. The diluent for the iminoheterocyclic carboxamide or carbothiamideis preferably the same as that for the nickel salt but can also beacetone, ethyl acetate, benzene, acetonitrile, dioxane and the like.

The nickel salt can also be prepared in a one-step process whereinformation of the iminoheterocyclic carboxamide or carbothiamide (as, forexample, by condensation of the appropriate aldehyde and cyanoacetamideor cyanothioacetamide) and subsequent chelation with the nickel salt arecarried out in the same phase without prior separation. The isolatednickel compounds prepared by either method can be used as such, or canbe purified, as by recrystallization from a suitable solvent, extractionwith a Suitable solvent, etc. In the case of nickel compounds of theinvention prepared in aqueous medium, it is preferred to digest theproduct with an organic medium such as dimethylformamide,dimethylsulfoxide and the like to induce crystallinity prior to use.

The iminoheterocyclic carboxamides (or carbothiamides) used to form thenickel salts of this invention can be prepared in various way. Forexample, the carboxamides of the pyrans and particularly the coumarinscan be prepared by condensing the appropriate aldehyde and particularlysalicylaldehyde with cyanoacetamide or an N-alkyl substitutedcyanoacetamide using the methods of Curtis et al., J. Chem. Soc., 123,3130-40 (1923) or Schiemenz, Ber. 95, 485 (1962). The carbothiamides canalso be prepared in the same manner using cyanothiacetamide or theN-alkyl substituted cyanothiacetamide. The carboxamides (orcarbothiamides) of the thiopyrans can also be prepared in the samemanner using the thioaldehydes. The carboxamides (or carbothiamides) ofthe pyridines can be prepared by condensing phenylpropargylaldehyde withcyanoacetamide or cyanothiacetamide, as the case may be, followed bytreatment with a primary amine. The carboxamides of other 6-memberednitrogen-containing ring compounds, i.e., the pyrimidines, pyridazines,pyrazines and triazines can be prepared by alkylating the carboxamide orcarbothiamide of the appropriate amino-substituted ring compound with analkyl or aryl halide followed by treatment with a base such as potassiumhydroxide. carboxamides of the oxazines and thiazines can be prepared byheating an o-aminophenol (or o-aminobenzenethiol) with 2-cyano-2,2-bisphenoxyacetamide; and the carboxamides of the oxadiazines andthiadiazines can be prepared by heating an acylhydrazide (orthioacylhydrazide) with Z-cyano- 2,2-bisphenoxyacetamide. Thecarboxamides of the thiazolines and imidazolines can be prepared byheating an N-substituted urea, thiourea or guanidine with 2-cyano-2,2-bisphenoxyacetamide; and the carboxamides of the pyrrolines can beprepared by condensing an amide of glyoxylic acid with cyanoacetamide.In the above preparations of the carboxamides of the oxazines,thiazines, triazines, oxadiazines, thiadiazines and thioazolines, afinal treatment with a base or the use of base in subsequent reactionwith the nickel salt may be necessary to facilitate ring closure. Thecarboxamides of the other S-membered ring compounds, i.e., thedihydrofurans, dihydrothiophenes, and oxazolines can be prepared insimilar manner. For example, the carboxamides of the dihydrofurans canbe prepared according to the methods of Ito et al., Tetrahedron Letters,3659 (1965), the carboxamides of the dihydrothiophenes by the samemethods except that the sulfur analogs of Itos carbonyl compounds areused, and the carboxamides of the oxazolines by heating an alkyl or arylcarbamate with 2-cyano-2,2-bisphenoxyacetamide, followed by treatmentwith base. The substituted aldehydes can be prepared from the phenolusing such known reactions as the Reimer-Tiemann reaction, the Dufireaction, or the Vilsmeier reaction, etc. (see Die Methoden derOrganischen Chemie, 4th ed., Sauerstotf II, pages -412, by Houben-Weyl,George Thieme Verlag, Stuttgart, 1954).

The nickel salts of this invention are characterized by being insolublein water and litho varnish and highly colored. They are of value aspigments in numerous applications but have particular value as pigmentsin exterior masstone applications, as for example, in automotivefinishes.

The invention will be illustrated by reference to the following examplesin which all percentages and parts are by weight unless otherwisespecified.

In the examples, the nickel salts were evaluated as pigments bypreparing paper drawouts thereof and determining the color visually. Theinks used for the drawouts were prepared by mulling the nickel compoundin litho varnish to form a masstone ink, and then, if desired, reducingthe ink with a White paste, to form a tint ink.

EXAMPLE 1 A solution of 2.4 parts of nickel (II) chloride hexahydrate inparts of anhydrous methanol was added with stirring to a solution of 3.8parts of 2-iminocoumarin-3-carboxamide (prepared by reacting 10 parts ofsalicylaldehyde with 10 parts of cyanoacetamide in parts of water and 1part of 10% potassium hydroxide and permitting to stand overnight) inparts of warm methanol containing 0.5 part of sodium. An orange-redsolid (97% yield based on the coumarin) which was insoluble in benzene,chloroform, ethylene glycol monomethyl ether, pyridine,dirnethylformamide, 1:1 benzeneethanol, and water was removed from thesolution by filtration, and extracted once with methanol to remove anyunreacted starting material, washed with fresh meth anol and then driedat 20 C. under vacuum.

The solid product, on analysis for C H N NiO gave: Calculated (percent):Carbon, 55.47; Hydrogen, 3.26; Nitrogen (Dumas), 12.94; Nickel (DirectAsh), 13.55. Found (percent): Carbon, 55.12; Hydrogen, 3.35; Nitrogen(Dumas), 12.71; Nickel (Direct Ash), 13.1, indicating that the productwas the nickel salt of Z-iminocoumarin-3-carboxamide. The masstone ink(orangered) when used in a paper drawout and exposed in a Fade-Ometerindicated very good light fastness.

7 EXAMPLE 2 A mixture of 25.8 parts of 2-hydroxy-l-naphthaldehyde and12.6 parts of cyanoacetamide was dissolved in 300 parts of absoluteethanol by heating on a steam bath, and piperidine drops) was added tothe solution with swirling. The solution was allowed to sit overnightafter which time the crystals of Z-imino-5,6-benzocoumarin-3-carboxamide which formed were removed by filtration and washed withabsolute ethanol. The crystals recovered above were dissolved in 3,000parts of dimethylformamide at 100 C., and a solution of 17.1 parts ofnickel acetate tetrahydrate in 300 parts of methanol added withagitation and the mixture heated on a steam bath for a few minutes,after which time the mixture was cooled and the nickel salt recovered byfiltration, washed with dimethylformamide, then Z-methoxyethanol andfinally with methanol, and dried. The nickel salt of2-imino-5,6-benzocoumarin-3-carboxamide (yield of 82% based on thecoumarin) was a red pigment which analyzed 9.73% nitrogen (Dumas) and10.6% nickel by direct ash (calculated for C H N NiO,,, 10.52% nitrogen,and 11.01% nickel). The masstone ink (brownish maroon) and the tint ink(brownish red) both exhibited excellent light fastness when paperdrawouts thereof were exposed in a fadeometer. The :pigment of thisexample was further evaluated by comparing it in a thermosetting acrylicenamel to a blend of equal depth prepared from molybdate orange andquinacridone violet. (Quinacridones are commercially useful pigmentswidely employed in automotive finishes because of their high degree oflight fastness.) Weatherometer and sub-tropical exposures of the panelsresulted in less darkening in the case of the pigment of Example 2 thanin the case of the quinacridone violet-molybdate orange blend.

EXAMPLES 3 to 25 In each of these examples, the nickel salts of theinvention were prepared according to the following general procedure.The desired 2 iminocoumarin 3 carboxamide which was to be reacted withthe nickel acetate was first prepared by condensing the appropriatealdehyde and cyanoacetamide dissolved in a minimum of anhydrous ethanol,at boiling temperature, if necessary, in the preseuce of a few drops ofpiperidine and permitting the reaction mixture to stand untilcrystallization was complete, after which time the crystals of theZ-iminocoumarin-3-carboxamide which formed were removed by filtrationand washed with anhydrous ethanol. The nickel salt of the2-imino-coumarin-3-carboxamide was then prepared by dissolving thecrystals obtained above in a suitable solvent (using heat, itnecessary), adding nickel acetate tetrahydrate to the solution as asolution in methanol with agitation, and continuing the agitation (usingheat, if necessary) until the desired nickel salt formed. The nickelsalt was next removed from the reaction medium by filtration orcentrifugation, and the nickel salt washed thoroughly first with thesame solvent as was used for its formation and then wtih methanol anddried (at 100 C.) under vacuum. Details for these examples and theproducts obtained are tabulated below in Table 1.

TABLE 1.NICKEL SALT OF 2-11VHNOCOUMARIN-3-CARBOXAMIDE Yield. Example No.Aldehyde Solvent 1 Analog percent Formula Color 3 E-rnethylsalicylaldehyde DMF (i-methyl- 78 C22H1 N4N104 O R 4-methylsalicylaldehyde M C 7methyl M CzzHrsN 4N1 O 4 O 3-methy1sal1eylnldehydeE 8-rnethyl 20 O22HIBN4N104 0 fi-tert-octyl salicylaldehyd 38C3aH4nN4NiO4 OR 3,5-d1methyl saliey1aldehyde 80 C24 22N4Ni04 O3-tert-butyl-5-methyl salieylald 74 C31JH34N4N104 O 5 tert-butyl 3methyl salicylaldehyde 31 Ca0H34N4N104 O S-chloro salieylaldehyde 54C2DH12C12N4N104 R 5-tert-butyl-3-chloro sallcylaldehyd6tert-butyl-8-ohloro 78 CzaHzaClzNtNiO 4 R 3,5-dichloro salieylaldehyde.6,8-dichl0ro 84 C20HwCliN4Ni04 R 5-brom0 salicylaldehyde. MC fi-hromo 71CznHizBr2N4NiO M 3,5-dibromo salicylaldehyde MC 6,8-d1bron1o 7C2DH1nBr4N4NiO B R 2,4-dihydroxybenza1dehyde. DMF 7-hydroxy 94CZIJHHN4N106 O D MF 6d CzzHiaNqNiOb O R DIHF 55 CzzHmNiNlOa O IVICs-methoxy 86 CgzHmN4NiOo, O

IMO fi-methylthio 7 C22H1 N4N104S2 O 4-trifluoromethyl salicylaldehyd M7-trifluoromethyl 50 CzzHnFuN4NiO M 5-nitro salicylaldehyde MC 1 DMF6-nitro 47 CzuHmNaNiOg OR S-nitro 7 CzaHrzNsNlOa O R 6-ph enylazo 70Ca2H22NaN104 B R 7-dimethylamino C24H24NON10| R 6,7-b enzo 67C2aHiaN4NiO4 B Analyses, percent Hydrogen Nitrogen (Dumas) Nickel (bydirect ash) Theory Found Theory Found Theory Found 12. 15 12. 04 12. 7311. 9 12. 15 11. 69 12. 73 11. 76 12. 15 l2. 13 12. 73 10. 69 8. 52 8.27 8. 93 9. 4 11. 11. 72 12. 00 10. 84 9. 77 10. 48 10. 2 1 9. 82 9. 7710. O9 10. 24 10. 03 11. 16 ll. 25 ll. 69 11. 0 9. 12 8. 89 9. 66 9. 049. 82 9. 92 10. 28 9. S5 9. 48 9. 07 9. 93 9. 7 7. 48 6. 9O 7. 84 7. 812.05 11. 66 12. 62 11.63 11. 36 11. 37 11. 90 11. 6 11. 36 11. 45 11.90 11. 6 11.36 11.28 11.90 11. 6 10. 67 10. 11. 17 5 11. 19 9. 86 10. 0410. 31 9. 82 16. 07 15. 53 11. 22 10. 6 15. 03 14. 90 10. 50 10. 2 17.48 17. 31 9. 15 8. 8 16.19 15 11. 30 10. 8 10. 51 10. 16 11. O1 10. 6

1 DMF dimethylformamide; MC =2-methoxyethanol; E ethanol; M =1net-hano1;M O D MF =2-meth0xyethanol; dimethylionnaruide (2 1) Based on aldehyde.

3 O =orange; R =rcd; O R =orauge-red; M=maroon; B R. =brownlshred; B=brown.

4 Also contained 25.4% chlorine (theory, 24.85%).

5 As dimethylglyoxime, using perchloric acid digestion.

9 EXAMPLE 26 To an aqueous solution containing 1.72 parts of2-hydroxy-l-naphthaldehyde, 0.66 part of 85 potassium hydroxide and 15parts of water was added a solution of 0.84 part cyanoacetamide in 15parts of water, and the mixture blanketed with nitrogen. After 2 hours,the bright yellow solid was removed from the mixture and washed withwater. The Z-imino 5,6 benzocoumarin-3-carboxamide product (1.62 parts,68% of theory) contained 11.7% nitrogen (theory, 11.8%) and fiuorescedunder ultraviolet light.

To a mixture of 0.5 part of the above iminocoumarin and 0.25 part ofnickel chloride hexahydrate ground to a fine slurry in 5 parts of waterwas added 300 parts water and 2 parts of sulfuric acid. The solutionwhich formed was filtered to remove undissolved solids and then madebasic with a solution of 0.53 part of sodium hydroxide in 5 parts ofwater. The nickel salt which formed (designated product A) was removedfrom the mixture by filtration, washed with water and then dried for 7hours at 100 C. and 0.1 mm. pressure. X-ray analysis of the nickel saltshowed little, if any, crystallinity and 3 broad diffuse bands unlikethe sharp crystalline lines of the nickel salt of Example 2.

Product A was next ground with water, filtered, heated with 20 parts ofdimethylformamide at 100 C. for 2 hours and then recovered. This product(designated product B), after drying for 8 hours at 100 C. and 0.05 mm.pressure exhibited, on X-ray analysis, basically the same pattern as thenickel salt of Example 2, the crystallinity, however, being lower with aslight shift in the spacing at 7 A. Product B contained 10.64% nitrogen(theory 10.52%) and 10.92% nickel (theory 11.01%) and gave a masstonecolor of red.

EXAMPLE 27 The nickel salt of Example 22 was produced in a one stepprocess by mixing at room temperature a solution of 1.67 parts of3-nitrosalicylaldehyde and 0.84 part of cyanoacetamide in 37 partsZ-methoxyethanol with a soluafter which time the solid was removed byfiltration. The filtrate was next reduced in volume, and a second cropof solid was recovered as above. The two crops of solid were combinedand recrystallized from 95% ethanol, giving 2.3 parts of a yellow,crystalline solid which was identified as2-oximinocoumarin-3-carboxamide [decomposed at 260 C. without definitelymelting and contained on analysis for C H N O 59.50% carbon (theory,58.82%), 3.97% hydrogen (theory, 3.95%) and 13.31% nitrogen (theory,13.72%)].

To a solution of 1.70 parts of the 2-oximinocoumarin- 3-carboxamideobtained above in 150 parts of boiling methanol was added a solution of104 parts of nickel acetate tetrahydrate in 50 parts of methanolfollowed by a solution of 0.55 part of 85% potassium hydroxide in 50parts of methanol. The mixture was next filtered to remove a trace ofbrown impurity, the filtrate reduced in volume by distilling off most ofthe solvent, and the run stored at 05 C. After several days, the nickelsalt which had formed was removed by filtration and washed withmethanol. The orange-brown product yield based on coumarin) wasidentified as the nickel salt of 2-iminocoumarin-3-carboxamide-N-oxideand, on analysis for C H N NiO contained 51.2% carbon (theory, 51.65%),3.6% hydrogen (theory, 3.03%) and 12.17% nickel (theory, 12.62%). Asecond crop of solid which was obtained by diluting the latter filtratewith water raised the total yield to 63%. The masstone ink was atransparent reddish-brown and the tint ink a reddish tan.

EXAMPLES 29 TO 32 The general procedure of Examples 3 to was repeatedexcept that in these examples salicylaldehyde was condensed with thefollowing substituted cyanoacetamides: N-phenylamino cyanoacetamide(Example 29); N-benzaliminocyanoacetamide (Example 30);N-acetamidocyanoacetamide (Example 31) andN-Z-pyridylmethylcyanoacetamide (Example 32). Details, analysis andevaluation of the nickel salts of these examples are given below inTable 2.

TABLE 2.-NICKEL SALT Analyses, percent Nitrogen Nickel Carbon Hydrogen(Dumas) (direct ash) Ex. Yield, Color, N 0 Solvent 1 percent 2 FormulaTheory Found Theory Found Theory Found Theory Found masstone 88CaaHzrNeNiO; 62. 47 62. 6 3. 93 4. 0 13. 66 13. 74 9. 54 9. 1 Brown. 57Ca4H24NaNiO4 63. 88 64. 37 3. 78 4. 25 13. 15 13. 9. 18 5. 67 Red. 95CziHtONaNlOt 52. 68 52. 44 3. 68 4. 24 15. 36 15. 01 10. 73 10. 22Brown. 74 Cs2H2-rNaNiO4-2H2O 59. 01 58. 91 4. 33 4. 36 12. 91 13. 31 9.01 9. 5 Red-brown.

1 MC=2-methoxyethanol; M=methanol. 2 Based on iminocoumarin.

tion of 1.24 parts of nickel acetate tetrahydrate and 1.00 EXAMPLE 33part sodium acetate in 16 parts of methanol, permitting the mixture tostand for 4 days, and then recovering the orange-red solid which formedby filtration and washing the solid with Z-methoxyethanol. To thefiltrate (including washings) was added a solution of 0.09 part ofpotassium hydroxide in 5 parts of 2-methoxyethanol and, after permittingto set for 1 day, a second crop of solid was filtered off and washedwith methanol. Third and fourth crops of solid were recovered in thesame manner as above except that a methanolic solution of potassiumhydroxide was used and the mixtures permitted to stand for 5 days and 8days respectively prior to filtration. The fourth crop after drying for5 hours at room temperature and 0.15 mm. pressure was found to contain14.64% nitrogen (theory, 15.03%) and 11.2% nickel (theory, 10.50%).

EXAMPLE 28 A mixture of 3.76 parts of 2-iminocoumarin-3-carboxamide and2.00 parts of hydroxylarnine hydrochloride in 100 parts of 95 ethanolwas stirred mechanically for several hours and the mixture allowed tostand overnight,

The procedure of Example 3 was repeated except that salicylaldehyde wascondensed with cyanothioacetamide. The nickel salt was a brownish-redpigment which analyzed 11.6% nitrogen (Kjeldahl), 12.07% nickel and13.6% sulfur (calculated for C H N NiO S 12.05% nitrogen, 12.62% nickeland 13.78% sulfur).

EXAMPLES 34 TO 38 Mixed nickel salts of 2-iminocoumarin-3-carboxamidewere prepared by adding a solution of a mixture of the2-iminocoumarin-3-carboxamide prepared in Example 1 or the 5,6-benzoanalog prepared in Example 2 and various second chelating agents in asolvent to a solution of the calculated amount of nickel acetatetetrahydrate in methanol. The solid which formed was filtered off,washed well with methanol and dried for several hours at C. under 0.1mm. pressure. The mixed salt formation was established by X-rayanalysis, as compared with analyses for the individual salts. Detailsfor these examples and analyses for and evaluation of the productsobtained are given in Table 3.

22 What I claim and desire to protect by Letters Patent is: 1. A nickelsalt having the formula NiA where R is selected from the groupconsisting of hydrogen, NHalkyl groups containing 1 to 20 carbon atoms,

groups with the further provision that R" and R'" together can also forma benzene ring and that at least one of R", R" and R" is hydrogen; A isan anion selected from the group consisting of halide, alkanoate,thiocyanate, cyanide, sulfate, ni- 45 trate, phosphate and hydroxide; mis or 1; n is l or 2;

5 A NHR l. l RI!! 8 N/ 1 J RI!!! 2O 2O NHacyl groups wherein the acylportion is alkanoyl of 2 to carbon atoms, benzoyl and phenylacetyl, NHphenyl, -NHnaphthyl, NHxylyl, NH 4 methoxyphenyl, NH-4-chlorophenyl,NHbenzyl, NHphenethyl, N CHphenyl, N=CHnaphthyl, N CHxylyl,-N=CH-4-methoxyphenyl, N CH-4-chlorophenyl, picolyl, methylpicolyl anddimethylpicolyl; R is selected from the group consisting of hydrogen,hydroxy and alkyl groups containing 1 to 20 carbon atoms; X is oxygen orsulfur; R is hydrogen or together with R" forms a benzene ring; R", R"and R'"' are selected from the group consisting of hydrogen, alkylgroups containing 1 to 8 carbon atoms, halogen, lower alkoxy, nitro,trihalomethyl, hydroxyl, diloweralkylamino, loweralkylthio, 4O phenylazo and benzene sulfonyl v is the valence of an anion A.

2. The nickel salt of claim 1 which is the nickel salt of2-irnino-5,6-benzocoumarin-3-carboxamide.

3. The nickel salt of claim 1 which is the nickel salt ofZ-imino-6-tert-octylc0umarin-3carhoxamide.

References Cited UNITED STATES PATENTS 3,369,029 2/1968 Augstein et al.260-3452 00 HENRY R. J ILES, Primary Examiner I. M. FORD, AssistantExaminer US. Cl. X.R.

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